Joint module and multi-joint modular robot arm

ABSTRACT

A joint module has a base, a motion mechanism, a linear driving mechanism, a driving motor assembly, and a transmission. The motion mechanism, the linear driving mechanism, and the driving motor assembly are disposed on the base. The transmission is disposed between the linear driving mechanism and the driving motor assembly. A first transmitting assembly and a second transmitting assembly of the motion mechanism are disposed on the base in parallel. A first linear driving assembly and a second linear driving assembly of the linear driving mechanism are non-coaxial and are disposed on the base in parallel. A first wheel transmitting assembly of the transmission is connected to the driving motor assembly and the first linear driving assembly. A second wheel transmitting assembly of the transmission is connected to the driving motor assembly and the second linear driving assembly.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a joint module and a multi jointmodular robot arm, and more particularly to a joint module and a multijoint modular robot arm that may improve the flexibility of the multijoint modular robot arm.

2. Description of Related Art

Conventional multi joint modular robot arms are applied to theautomation industry and are controlled by programs to do tasks such aspick-and-place of objects, carriage, welding, polishing, and paintingautomatically. The conventional multi joint modular robot arm may be asix-axis robot arm having six rotating drivers connected vertically, orhaving a selective compliance articulated robot arm (SCARA), or having arobot arm combining two rotating drivers connected in parallel and alinear driver, or having a robot arm combining three rotating driversconnected in parallel. The six-axis robot arm having six rotatingdrivers connected vertically has more freedom and is widely used.

The six-axis robot arm is composed by the six rotating drivers connectedvertically. Each rotating driver is a joint module. Each rotating drivermay be composed of a motor and a harmonic gear, or a worm wheel and aworm assembly. Each rotating driver is only capable of a single axisrotation. A manufacturing cost of each rotating driver is high by usingthe specific harmonic gear. In operation of the six-axis robot arm, theend movement path of the six-axis robot arm is not flexible enough.

For overcoming the problems that each rotating driver is only capable ofthe single axis rotation and the end movement path of the six-axis robotarm is not flexible enough, a prior joint module has been invented bythe inventor of the invention. With reference to FIGS. 15 to 18, theprior joint module has a base 70, two screw linear driving assemblies71, 72, and two motors 73, 74. The two screw linear driving assemblies71, 72 and two motors 73, 74 are disposed on the base 70. The two screwlinear driving assemblies 71, 72 are arranged up and down in parallel.The two motors 73, 74 are respectively connected to the two screw lineardriving assemblies 71, 72. Two linear motion elements of the two screwlinear driving assemblies 71, 72 are connected to a motion element 77 bytwo connecting rod assemblies 75, 76 respectively. The two connectingrod assemblies 75, 76 are connected to the motion element 77 inparallel. The two motors 73, 74 respectively drive the two connectingrod assemblies 75, 76 by the two screw linear driving assemblies 71, 72.The motion element 77 driven by the two connecting rod assemblies 75, 76could rotate top to bottom and left to right for biaxial sphericalrotating movement. The problems of each rotating driver only capable ofthe single axis rotation and the end movement path of the six-axis robotarm being not flexible enough can be overcome by the prior joint module.The problem of the single axis joint module using the harmonic gear issolved by the prior joint module. The problem of the single axis jointmodule using the worm assembly and the worm wheel is solved by the priorjoint module, too. In the prior joint module capable of biaxialspherical rotating movement, the two motors 73, 74 are directlyconnected to the two screw linear driving assemblies 71, 72 and the twoconnecting rod assemblies 75, 76 for connecting the motion element 77.In a limited space and to meet different requirements, a reduction ratioand a torque speed of the prior joint module are hard to change. Thereduction ratio and the torque speed of the prior joint module are noteasy to customize. To overcome the shortcomings, the present inventionprovides a joint module and a multi joint modular robot arm to mitigateor obviate the aforementioned problems.

SUMMARY OF THE INVENTION

The objective of the invention is to provide a joint module and amulti-joint modular robot arm that may solve the problems that eachrotating driver is only capable of the single axis rotation and the endmovement path of the six-axis robot arm is not flexible enough, andimproves the practicality of the prior joint module that is capable ofbiaxial spherical rotating movement.

The joint module has a base, a motion mechanism, a linear drivingmechanism, a driving motor assembly, and a transmission. The base has acentral axis. The central axis is defined on the base. The motionmechanism is disposed on the base and has a motion element, a firsttransmitting assembly, and a second transmitting assembly. The firsttransmitting assembly and the second transmitting assembly are disposedon the base in parallel and are connected to the motion element. Themotion element is driven for having a spherical movement centered on thecentral axis of the base.

The linear driving mechanism is disposed on the base and has a firstlinear driving assembly and a second linear driving assembly. The firstlinear driving assembly and the second linear driving assembly arenon-coaxial and are disposed on the base in parallel. The first lineardriving assembly has a first linear moving member and a first screwassembly. The first linear moving member is connected to the firsttransmitting assembly. The first screw assembly is connected to thefirst linear moving member. The first linear moving member is driven bythe first screw assembly to reciprocate along the central axis. Thesecond linear driving assembly has a second linear moving member and asecond screw assembly. The second linear moving member is connected tothe second transmitting assembly. The second screw assembly is connectedto the second linear moving member. The second linear moving member isdriven by the second screw assembly to reciprocate along the centralaxis.

The driving motor assembly is disposed on the base. The driving motorassembly has a first motor having a first output rod and a second motorhaving a second output rod.

The transmission is disposed between the linear driving mechanism andthe driving motor assembly and has a first wheel transmitting assemblyand a second wheel transmitting assembly. The first wheel transmittingassembly is connected to the first output rod of the driving motorassembly and the first linear driving assembly. The second wheeltransmitting assembly is connected to the second output rod of thedriving motor assembly and the second linear driving assembly.

The joint module has the following advantages:

1. Biaxial spherical rotating movement: in the invention, the firsttransmitting assembly and the second transmitting assembly are disposedon the base in parallel to connect to the motion element. The firsttransmitting assembly is connected to the first motor by the firstlinear driving assembly and the first wheel transmitting assembly. Thesecond transmitting assembly is connected to the second motor by thesecond linear driving assembly and the second wheel transmittingassembly. The first transmitting assembly is driven by the first motorindependently. The second transmitting assembly is driven by the secondmotor independently. Thus, the motion element can be driven toaccomplish the biaxial spherical rotating movement.

2. High rigidity: the first transmitting assembly and the secondtransmitting assembly are disposed on the base in parallel to connect tothe motion element. The first transmitting assembly is connected to thefirst motor by the first linear driving assembly and the first wheeltransmitting assembly. The second transmitting assembly is connected tothe second motor by the second linear driving assembly and the secondwheel transmitting assembly. The first transmitting assembly is drivenby the first motor alone. The second transmitting assembly is driven bythe second motor alone. By the transmitting structures in the jointmodule, the motion element has high rigidity in the biaxial sphericalrotating movement.

3. Changeable reduction ratio: the reduction ratio of the driving motorassembly and the transmission is adjustable. The reduction ratio isvariable when the size and the structure of the joint module are notchanged. The joint module can be reused and is easy to customize Thejoint module can provide the excellent torque speed by the combinationof the driving motor assembly and the transmission. The efficiency ofthe joint module is increased.

Furthermore, the base has a first end and a second end defined along thecentral axis of the base. The motion element is disposed at the firstend of the base. The first output rod of the driving motor assembly, thesecond output rod of the driving motor assembly, the first linear movingmember, and the second linear moving member are juxtaposed in parallelon the base. The first wheel transmitting assembly and the second wheeltransmitting assembly are disposed at the second end of the base. Thus,the first wheel transmitting assembly and the second wheel transmittingassembly are easy to assemble and replace. The spatial configuration ofthe joint module is good.

Furthermore, the first motor and the second motor are stepper motors.The first wheel transmitting assembly and the second wheel transmittingassembly are pulley assemblies, sprocket assemblies, or gear assembliesfor connecting the first screw assembly and the second screw assembly ofthe linear driving mechanism. The technology of the stepper motors, thepulley assemblies, the sprocket assemblies, or the gear assemblies ismaturely developed and well known in the art. Components of the jointmodule are not specific. The manufacturing cost can be controlledeffectively.

In addition, the joint module uses a reducer with the stepper motors andthe wheel transmitting assemblies for having a high reduction ratio in alimited space without a harmonic gear reducer. The stepper motors arecapable of the forward driving and the backward driving and are used inthe joint module. The joint module has a high torque density ratio, alow price, and a high reliability to enhance the market competitiveness.

Furthermore, the joint module has a shell, a chamber, an opening, and anouter plate. The shell is disposed on the base. The chamber is formedbetween the shell and the base. The opening is formed on the shelladjacent to the first end of the base and communicates with the chamber.The outer plate is formed on the shell adjacent to the second end of thebase. The motion mechanism, the linear driving mechanism, the drivingmotor assembly, and the transmission are disposed in the chamber of thejoint module. The motion mechanism, the linear driving mechanism, thedriving motor assembly, and the transmission are protected by the shelland the base. The outer plate can be connected to a motion mechanism ofanother joint module.

Furthermore, the joint module has two strain gauges. The two straingauges are respectively disposed on the first transmitting assembly andthe second transmitting assembly for measuring deformations of the firsttransmitting assembly and the second transmitting assembly. The jointmodule may be combined with a force controlled system for doing abiaxial compliance movement.

The multi joint modular robot arm has multiple joint modules asdescribed. The joint modules are connected in series. Each two jointmodules are connected in series. The base of one of said two jointmodules is connected to the motion element of another one of said twojoint modules.

The multi joint modular robot arm has the joint modules connected inseries. Each joint module has the function of biaxial rotating movement.The combination of the joint modules in the multi joint modular robotarm is variable. The reduction ratio of each joint module may be changedby the transmission. The driving energy provided by the driving motorassembly can be applied efficiently. Each joint module has the functionof biaxial spherical rotating movement. Thus, the flexibility of themulti joint modular robot arm is good.

Furthermore, the reduction ratio of the driving motor assembly and thetransmission is adjustable and variable when the size and the structureof the joint module are not changed. The multi joint modular robot armcan be reused and is easy to customize The practicality of the multijoint modular robot arm is good.

Other objectives, advantages and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a joint module in accordance with thepresent invention;

FIG. 2 is another perspective view of the joint module in FIG. 1;

FIG. 3 is a top view of the joint module in FIG. 1;

FIG. 4 is a side view of the joint module in FIG. 1;

FIG. 5 is another side view of the joint module in FIG. 1;

FIG. 6 is an exploded perspective view of the joint module in FIG. 1,combined with a shell;

FIG. 7 is another exploded perspective view of the joint module in FIG.6;

FIG. 8 is a perspective view of the joint module in FIG. 1, combinedwith the shell;

FIG. 9 is a side view of a multi joint modular robot arm in accordancewith the present invention, showing two joint modules connected inseries;

FIG. 10 is a side view of another multi joint modular robot arm inaccordance with the present invention, showing three joint modulesconnected in series;

FIG. 11 is an operational side view of the multi joint modular robot armin FIG. 10;

FIG. 12 is an initial operational side view of the multi joint modularrobot arm showing an angle between the central axes of the two jointmodules being 0 degree;

FIG. 13 is an initial operational side view of the multi joint modularrobot arm showing an angle between the central axes of the two jointmodules being 45 degrees;

FIG. 14 is an initial operational side view of the multi joint modularrobot arm showing an angle between the central axes of the two jointmodules being 90 degrees;

FIG. 15 is a perspective view of a joint module in accordance with theprior art;

FIG. 16 is another perspective view of the joint module in FIG. 15;

FIG. 17 is a top view of the joint module in FIG. 15; and

FIG. 18 is a side view of the joint module in FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIGS. 1 and 2, a joint module 1 in accordance with thepresent invention comprises a base 10, a motion mechanism 20, a lineardriving mechanism 30, a driving motor assembly 40, and a transmission50. With reference to FIGS. 1 and 5, the base 10 has a central axis 100.The central axis 100 is defined on the base 10. The base 10 has a firstend 101 and a second end 102. The first end 101 and the second end 102are defined along the central axis 100 of the base 10. The base 10 hasan X axial direction, a Y axial direction, and a Z axial direction. TheY axial direction is perpendicular to the X axial direction. The Z axialdirection is perpendicular to the X axial direction and the Y axialdirection. A direction of the central axis 100 is the Z axial direction.

With reference to FIGS. 1 to 5, the joint module has a first slide rail11 and a second slide rail 12. The first slide rail 11 and the secondslide rail 12 are disposed on the base 10 at a spaced interval and areparallel with the central axis 100 of the base 10.

With reference to FIGS. 1 to 5, the motion mechanism 20 is disposed onthe base 10 and has a motion element 21, a first transmitting assembly22, and a second transmitting assembly 23. The first transmittingassembly 22 and the second transmitting assembly 23 are disposed on thebase 10 in parallel and are connected to the motion element 21. Themotion element 21 can be driven to have a spherical movement centered onthe central axis 100 of the base 10.

With reference to FIGS. 1 to 5, the motion element 21 is movablydisposed on the first end 101 of the base 10. The motion element 21 hasa motion part 210, an X axial rod 211, and a Y axial rod 212. The motionpart 210 has a connecting rod portion 213, a connecting end 215, and anend plate 214. The connecting rod portion 213 has two ends. Theconnecting end 215 is formed on one of the two ends of the connectingrod portion 213. The end plate 214 is disposed on the other one of thetwo ends of the connecting rod portion 213. The end portion 214 is usedas an outer connecting component. The X axial rod 211 and the Y axialrod 212 are independently disposed through the connecting end 215 of theconnecting rod portion 210.

With reference to FIGS. 1 to 5, the first transmitting assembly 22 has afirst transmitting member 221 and a second transmitting member 222. Thefirst transmitting member 221 has two ends, and one of the two ends ispivotally connected to the linear driving mechanism 30. Two ends of thesecond transmitting member 222 are pivotally connected to the other endof the first transmitting member 221 and the X axial rod 211,respectively. Thus, the X axial rod 211 is fulcrum, and the motion part210 is rotated along the Y axial direction by the linear drivingmechanism 30.

With reference to FIGS. 1 to 5, the second transmitting assembly 23 hasa first rod 231, a second rod 232, and a third rod 233. An end of thefirst rod 231 is pivotally connected to the linear driving mechanism 30.Two ends of the second rod 232 are pivotally connected to another end ofthe first rod 231 and an end of the third rod 233 respectively. Anotherend of the third rod 233 is pivotally connected to the Y axial rod 212.Thus, the Y axial rod 212 is fulcrum, and the motion part 210 is rotatedalong the X axial direction by the linear driving mechanism 30.

With reference to FIGS. 1 to 5, for improving the flexibility of themotion mechanism 20, the motion mechanism 20 further has a motion seat24. The motion seat 24 is disposed on the base 10 and is rotated alongthe X axial direction when the Y axial direction is a fulcrum. An end ofthe motion seat 24 at the Y axial direction is connected to an X axialpivoting component 241 for pivotally connecting the second transmittingmember 222. Another end of the motion seat 24 at the Y axial directionis connected to a Y axial pivoting component 242 for pivotallyconnecting the second rod 232. A pivoted portion between the motion seat24 and the second rod 232 is located beside a pivoted portion betweenthe first rod 231 and the second rod 232.

With reference to FIGS. 1 to 5, the linear driving mechanism 30 isdisposed on the base 10 and has a first linear driving assembly 31 and asecond linear driving assembly 32. The first linear driving assembly 31and the second linear driving assembly 32 are non-coaxial and aredisposed on the base 10 in parallel. The first linear driving assembly31 has a first linear moving member 311 and a first screw assembly 312.The first linear moving member 311 is connected to the firsttransmitting assembly 22. The first screw assembly 312 is connected tothe first linear moving member 311. The first linear moving member 311is driven by the first screw assembly 312 to move reciprocally along thecentral axis 100. The second linear driving assembly 32 has a secondlinear moving member 321 and a second screw assembly 322. The secondlinear moving member 322 is connected to the second transmittingassembly 23. The second screw assembly 322 is connected to the secondlinear moving member 321. The second linear moving member 321 is drivenby the second screw assembly 322 to move reciprocally along the centralaxis 100. Furthermore, the first linear moving member 311 is pivoted tothe first transmitting member 221 of the first transmitting assembly 22.The second linear moving member 321 is pivotally connected to the firstrod 231 of the second transmitting assembly 23.

With reference to FIGS. 1 to 5, the first screw assembly 312 has a firstscrew 313 and a first barrel 314. The first barrel 314 is disposedaround the first screw 313, is fixedly disposed in the first linearmoving member 311, and is located between the first screw 313 and thefirst linear moving member 311. The second screw assembly 322 has asecond screw 323 and a second barrel 324. The second barrel 324 isdisposed around the second screw 323, is fixedly disposed in the secondlinear moving member 321, and is located between the second screw 323and the second linear moving member 321. A distal end of the first screw313 is connected to a first bearing seat 316 disposed on the base 10. Adistal end of the second screw 323 is connected to a second bearing seat326 disposed on the base 10.

With reference to FIGS. 1 to 5, the first linear driving assembly 311has a first sliding block 315. The first sliding block 315 is slidablydisposed on the first slide rail 11. The second linear driving assembly321 has a second sliding block 325. The second sliding block 325 isslidably disposed on the second slide rail 12.

With reference to FIGS. 1 to 5, the driving motor assembly 40 isdisposed on the base 10. In addition, the driving motor assembly 40 isdisposed on the base 10 by a supporting seat. The driving motor assembly40 has a first motor 41 having a first output rod and a second motor 42having a second output rod. The first motor 41 and the second motor 42are stepper motors and have high torque density ratios, respectively.The first output rod of the first motor 41, the second output rod of thesecond motor 42, the first linear driving assembly 31, and the secondlinear driving assembly 32 are juxtaposed in parallel on the base 10.

With reference to FIGS. 1 to 5, the transmission 50 is disposed betweenthe linear driving mechanism 30 and the driving motor assembly 40. Thetransmission 50 has a first wheel transmitting assembly 51 and a secondwheel transmitting assembly 52. The first wheel transmitting assembly 51is connected to the first output rod of the first motor 41 and the firstlinear driving assembly 31. The second wheel transmitting assembly 52 isconnected to the second output rod of the second motor 42 and the secondlinear driving assembly 32. Moreover, the first screw 313 of the firstscrew assembly 312 is connected to the first wheel transmitting assembly51. The second screw 323 of the second screw assembly 322 is connectedto the second wheel transmitting assembly 52. The first wheeltransmitting assembly 51 and the second wheel transmitting assembly 52are pulley assemblies, sprocket assemblies, or gear assemblies forproviding a reduction function. In the embodiment of the joint module,the first wheel transmitting assembly 51 and the second wheeltransmitting assembly 52 are pulley assemblies. The first wheeltransmitting assembly 51 and the second wheel transmitting assembly 52are disposed at the second end 102 of the base 10 for ease of assemblyand replacement. The reduction ratio of the transmission 50 may be from1:0.45 to 1:2.25. The driving energy provided by the driving motorassembly 40 can be applied efficiently. The reduction ratio of thedriving motor assembly 40 and the transmission 50 is adjustable. Thereduction ratio is variable when the size and the structure of the jointmodule 1 are not changed. The joint module 1 can be reused and is easyto customize

With reference to FIGS. 6 to 8, the joint module 1 has a shell 60, achamber, and an opening 61. The shell 60 is disposed on the base 10. Thechamber is formed between the shell 60 and the base 10. The opening 61is formed on the shell 60 adjacent to the first end of the base 10 andis in communication with the chamber of the joint module 1. The motionelement 21 passes through the opening 61. The motion mechanism 20, thefirst linear driving assembly 31, the second linear driving assembly 32,the first motor 41, the second motor 42, the first wheel transmittingassembly 51, and the second wheel transmitting assembly 52 are disposedin the chamber of the joint module 1. The joint module 1 further has anouter plate 62. The outer plate 62 is formed on the shell 60 adjacent tothe second end 102 of the base 10. The outer plate 62 can be connectedto a motion element 21 of another joint module 1.

Furthermore, the joint module 1 may have two strain gauges. The twostrain gauges are respectively disposed on the first transmittingassembly 22 and the second transmitting assembly 23 for respectivelymeasuring deformations of the first transmitting assembly 22 and thesecond transmitting assembly 23. The joint module 1 may be combined witha force controlled system for moving accurately.

With reference to FIGS. 9 and 10, a multi joint modular robot arm A, Bin accordance with the present invention comprises multiple jointmodules 1A, 1B, 1C as described in FIGS. 1 to 8. The joint modules 1A,1B, 1C are connected with each other in series. Each two joint modules1A, 1B, 1C are connected in series. The base 10 of one of said two jointmodules 1A, 1B, 1C is connected to the motion element 21 of another oneof said two joint modules 1A, 1B, 1C. The end plate 214 of the motionelement 21of one of the joint modules 1A, 1B, 1C is fixedly connected tothe outer plate 62 of another one of the joint modules 1A, 1B, 1C forconnecting in series.

Take the joint modules having the shell 60 connected in series as anexample. With reference to FIG. 9, the multi joint modular robot arm Ahas a first joint module 1A and a second joint module 1B connected tothe first joint module 1A in series. The independent first joint module1A and the independent second joint module 1B both have two degrees offreedom. Two ends of the first joint module 1A are respectivelyconnected to the second joint module 1B and a rotating driver 2. Aclamping apparatus 3 is connected to the second joint module 1B and isopposite to the first joint module 1A. The first joint module 1Acombined with the rotating driver 2 has three degrees of freedom. Thesecond joint module 1B combined with the clamping apparatus 3 has threedegrees of freedom. Thus, the multi joint modular robot arm A has sixdegrees of freedom. The multi joint modular robot arm A is equal to asix-axis robot in motion function.

With reference to FIG. 10, the multi joint modular robot arm B has afirst joint module 1A, a second joint module 1B, and a third jointmodule 1C. The second joint module 1B is connected to the first jointmodule 1A and the third joint module 1C in series. The first jointmodule 1A, the second joint module 1B, and the third joint module 1C allhave two degrees of freedom. A rotating driver 2 is connected to thefirst joint module 1A and is opposite to the second joint module 1B. Aclamping apparatus 3 is connected to the third joint module 1C and isopposite to the second joint module 1B. The first joint module 1Acombined with the rotating driver 2 has three degrees of freedom. Thethird joint module 1C combined with the clamping apparatus 3 has threedegrees of freedom. Thus, the multi joint modular robot arm B has eightdegrees of freedom. A human arm has seven degrees of freedom. Therefore,the multi joint modular robot arm B has more degrees of freedom than thehuman arm. Therefore, the multi joint modular robot arm B is flexible.With reference to FIG. 11, two multi joint modular robot arms B arerespectively disposed on two sides of a robot body C and generate themotions as the motion of the human arms.

The multi joint modular robot aim may have two joint modules or threejoint modules, but it is not limited thereto.

With reference to FIGS. 12, 13, and 14, the multi joint modular robotarm has two joint modules 1. The two joint modules 1 are connected inseries. A relative initial position between the two joint modules 1 canbe changed by a relative angular change between the connecting rodportion 213 and the end plate 214 in a connecting position of the twojoint modules 1. With reference to FIG. 12, in the connecting positionof the two joint modules 1, the connecting rod portion 213 is straight.The end plate 214 is vertically connected to a distal end of theconnecting rod portion 213. In the relative initial position between thetwo joint modules 1, an angle between the central axes 100 of the twojoint modules 1 is 0 degree.

With reference to FIG. 13, in the connecting position of the two jointmodules 1, the connecting rod portion 213 is straight. The end plate 214is connected to a distal end of the connecting rod portion 213 at anangle of 45 degrees. In the relative initial position between the twojoint modules 1, an angle between the central axes 100 of the two jointmodules 1 is 45 degrees. With reference to FIG. 14, in the connectingposition of the two joint modules 1, the connecting rod portion 213 isL-shaped. In the relative initial position between the two joint modules1, an angle between the central axes 100 of the two joint modules 1 is90 degrees. The angle between the central axes 100 can be changed by thechange of the connecting rod portion 213. Accordingly, the multi jointmodular robot arm has the joint modules 1A, 1B, 1C connected in series.Each joint module has the function of biaxial rotating movement. Thecombination of the joint modules in the multi joint modular robot arm isvariable. The reduction ratio of each joint module may be changed by thetransmission 50. The driving energy provided by the driving motorassembly 40 can be applied efficiently. The reduction ratio of thedriving motor assembly 40 and the transmission 50 is adjustable and isvariable when the size and the structure of the joint module are notchanged. The multi joint modular robot arm can be reused and is easy tocustomize The practicality of the multi joint modular robot arm is good.

What is claimed is:
 1. A joint module comprising: a base having a central axis defined on the base; a motion mechanism disposed on the base and having a motion element, a first transmitting assembly, and a second transmitting assembly, and the first transmitting assembly and the second transmitting assembly disposed on the base in parallel and connected to the motion element; wherein the motion element is driven for having a spherical movement centered on the central axis of the base; a linear driving mechanism disposed on the base and having a first linear driving assembly and a second linear driving assembly, and the first linear driving assembly and the second linear driving assembly being non-coaxial and disposed on the base in parallel; the first linear driving assembly having a first linear moving member connected to the first transmitting assembly; and a first screw assembly connected to the first linear moving member, wherein the first linear moving member is driven by the first screw assembly to reciprocate along the central axis; and the second linear driving assembly having a second linear moving member connected to the second transmitting assembly; and a second screw assembly connected to the second linear moving member, wherein the second linear moving member is driven by the second screw assembly to reciprocate along the central axis; a driving motor assembly disposed on the base and having a first motor having a first output rod and a second motor having a second output rod; and a transmission disposed between the linear driving mechanism and the driving motor assembly, and having a first wheel transmitting assembly connected to the first output rod of the driving motor assembly and the first linear driving assembly; and a second wheel transmitting assembly connected to the second output rod of the driving motor assembly and the second linear driving assembly.
 2. The joint module as claimed in claim 1, wherein the base has a first end and a second end defined along the central axis of the base, and the motion element is disposed on the first end of the base, and the first output rod of the driving motor assembly, the second output rod of the driving motor assembly, the first linear moving member, and the second linear moving member are juxtaposed in parallel on the base, and the first wheel transmitting assembly and the second wheel transmitting assembly are disposed at the second end of the base.
 3. The joint module as claimed in claim 2, wherein the first motor and the second motor are stepper motors; the first wheel transmitting assembly and the second wheel transmitting assembly are pulley assemblies, sprocket assemblies, or gear assemblies; the first screw assembly has a first screw connected to the first wheel transmitting assembly; and a first barrel disposed between the first screw and the first linear moving member; and the second screw assembly has a second screw connected to the second wheel transmitting assembly; and a second barrel disposed between the second screw and the second linear moving member.
 4. The joint module as claimed in claim 3, wherein the joint module has a shell disposed on the base; a chamber formed between the shell and the base; an opening formed on the shell adjacent to the first end of the base and communicating with the chamber; and an outer plate formed on the shell adjacent to the second end of the base; and the motion mechanism, the linear driving mechanism, the driving motor assembly, and the transmission are disposed in the chamber of the joint module.
 5. The joint module as claimed in claim 4, wherein the joint module has a first slide rail disposed on the base and being parallel with the first screw; and s second slide rail disposed on the base and being parallel with the first screw; the first linear driving assembly has a first sliding block slidably disposed on the first slide rail; and the second linear driving assembly has a second sliding block slidably disposed on the second slide rail.
 6. The joint module as claimed in claim 1, wherein the base has an X axial direction; a Y axial direction perpendicular to the X axial direction; a Z axial direction perpendicular to the X axial direction and the Y axial direction; and a direction of the central axis being the Z axial direction; the motion element has a motion part having a connecting rod portion, and the connecting rod portion having a connecting end; an X axial rod disposed through the connecting end of the connecting rod portion; and a Y axial rod disposed through the connecting end of the connecting rod portion; the first transmitting assembly has a first transmitting member having an end pivotally connected to the first linear moving member; and a second transmitting member having two ends pivotally connected to another end of the first transmitting member and the X axial rod respectively, wherein the X axial rod is fulcrum, and the motion part is rotated along the Y axial direction by the first transmitting assembly; the second transmitting assembly has a first rod, a second rod, and a third rod, an end of the first rod is pivotally connected to the second linear moving member, two ends of the second rod are pivotally connected to another end of the first rod and an end of the third rod respectively, and another end of the third rod is pivotally connected to the Y axial rod, wherein the Y axial rod is fulcrum, and the motion part is rotated along the X axial direction by the second transmitting assembly; and the motion mechanism has a motion seat, the motion seat is rotated along the X axial direction and is disposed on the base, an end of the motion seat at the Y axial direction is connected to an X axial pivoting component for pivoting the second transmitting member, another end of the motion seat at the Y axial direction is connected to a Y axial pivoting component for pivoting the second rod, and a pivoted portion between the motion seat and the second rod is located beside a pivoted portion between the first rod and the second rod.
 7. The joint module as claimed in claim 2, wherein the base has an X axial direction; a Y axial direction perpendicular to the X axial direction; a Z axial direction perpendicular to the X axial direction and the Y axial direction; and a direction of the central axis being the Z axial direction; the motion element has a motion part having a connecting rod portion, and the connecting rod portion having a connecting end; an X axial rod disposed through the connecting end of the connecting rod portion; and a Y axial rod disposed through the connecting end of the connecting rod portion; the first transmitting assembly has a first transmitting member having an end pivotally connected to the first linear moving member; and a second transmitting member having two ends pivotally connected to another end of the first transmitting member and the X axial rod respectively, wherein the X axial rod is fulcrum, and the motion part is rotated along the Y axial direction by the first transmitting assembly; the second transmitting assembly has a first rod, a second rod, and a third rod, an end of the first rod is pivotally connected to the second linear moving member, two ends of the second rod are pivotally connected to another end of the first rod and an end of the third rod respectively, and another end of the third rod is pivotally connected to the Y axial rod, wherein the Y axial rod is fulcrum, and the motion part is rotated along the X axial direction by the second transmitting assembly; and the motion mechanism has a motion seat, the motion seat is rotated along the X axial direction and is disposed on the base, an end of the motion seat at the Y axial direction is connected to an X axial pivoting component for pivoting the second transmitting member, another end of the motion seat at the Y axial direction is connected to a Y axial pivoting component for pivoting the second rod, and a pivoted portion between the motion seat and the second rod is located beside a pivoted portion between the first rod and the second rod.
 8. The joint module as claimed in claim 3, wherein the base has an X axial direction; a Y axial direction perpendicular to the X axial direction; a Z axial direction perpendicular to the X axial direction and the Y axial direction; and a direction of the central axis being the Z axial direction; the motion element has a motion part having a connecting rod portion, and the connecting rod portion having a connecting end; an X axial rod disposed through the connecting end of the connecting rod portion; and a Y axial rod disposed through the connecting end of the connecting rod portion; the first transmitting assembly has a first transmitting member having an end pivotally connected to the first linear moving member; and a second transmitting member having two ends pivotally connected to another end of the first transmitting member and the X axial rod respectively, wherein the X axial rod is fulcrum, and the motion part is rotated along the Y axial direction by the first transmitting assembly; the second transmitting assembly has a first rod, a second rod, and a third rod, an end of the first rod is pivotally connected to the second linear moving member, two ends of the second rod are pivotally connected to another end of the first rod and an end of the third rod respectively, and another end of the third rod is pivotally connected to the Y axial rod, wherein the Y axial rod is fulcrum, and the motion part is rotated along the X axial direction by the second transmitting assembly; and the motion mechanism has a motion seat, the motion seat is rotated along the X axial direction and is disposed on the base, and an end of the motion seat at the Y axial direction is connected to an X axial pivoting component for pivoting the second transmitting member, another end of the motion seat at the Y axial direction is connected to a Y axial pivoting component for pivoting the second rod, and a pivoted portion between the motion seat and the second rod is located beside a pivoted portion between the first rod and the second rod.
 9. The joint module as claimed in claim 4, wherein the base has an X axial direction; a Y axial direction perpendicular to the X axial direction; a Z axial direction perpendicular to the X axial direction and the Y axial direction; and a direction of the central axis being the Z axial direction; the motion element has a motion part having a connecting rod portion, and the connecting rod portion having a connecting end; an X axial rod disposed through the connecting end of the connecting rod portion; and a Y axial rod disposed through the connecting end of the connecting rod portion; the first transmitting assembly has a first transmitting member having an end pivotally connected to the first linear moving member; and a second transmitting member having two ends pivotally connected to another end of the first transmitting member and the X axial rod respectively, wherein the X axial rod is fulcrum, and the motion part is rotated along the Y axial direction by the first transmitting assembly; the second transmitting assembly has a first rod, a second rod, and a third rod, an end of the first rod is pivotally connected to the second linear moving member, two ends of the second rod are pivotally connected to another end of the first rod and an end of the third rod respectively, and another end of the third rod is pivotally connected to the Y axial rod, wherein the Y axial rod is fulcrum, and the motion part is rotated along the X axial direction by the second transmitting assembly; and the motion mechanism has a motion seat, and the motion seat is rotated along the X axial direction and is disposed on the base, an end of the motion seat at the Y axial direction is connected to an X axial pivoting component for pivoting the second transmitting member, another end of the motion seat at the Y axial direction is connected to a Y axial pivoting component for pivoting the second rod, and a pivoted portion between the motion seat and the second rod is located beside a pivoted portion between the first rod and the second rod.
 10. The joint module as claimed in claim 5, wherein the base has an X axial direction; a Y axial direction perpendicular to the X axial direction; a Z axial direction perpendicular to the X axial direction and the Y axial direction; and a direction of the central axis being the Z axial direction; the motion element has a motion part having a connecting rod portion, and the connecting rod portion having a connecting end; an X axial rod disposed through the connecting end of the connecting rod portion; and a Y axial rod disposed through the connecting end of the connecting rod portion; the first transmitting assembly has a first transmitting member having an end pivotally connected to the first linear moving member; and a second transmitting member having two ends pivotally connected to another end of the first transmitting member and the X axial rod respectively, wherein the X axial rod is fulcrum, and the motion part is rotated along the Y axial direction by the first transmitting assembly; the second transmitting assembly has a first rod, a second rod, and a third rod, an end of the first rod is pivotally connected to the second linear moving member, two ends of the second rod are pivotally connected to another end of the first rod and an end of the third rod respectively, and another end of the third rod is pivotally connected to the Y axial rod, wherein the Y axial rod is fulcrum, and the motion part is rotated along the X axial direction by the second transmitting assembly; and the motion mechanism has a motion seat, the motion seat is rotated along the X axial direction and is disposed on the base, an end of the motion seat at the Y axial direction is connected to an X axial pivoting component for pivoting the second transmitting member, another end of the motion seat at the Y axial direction is connected to a Y axial pivoting component for pivoting the second rod, and a pivoted portion between the motion seat and the second rod is located beside a pivoted portion between the first rod and the second rod.
 11. The joint module as claimed in claim 1, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 12. The joint module as claimed in claim 2, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 13. The joint module as claimed in claim 3, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 14. The joint module as claimed in claim 4, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 15. The joint module as claimed in claim 5, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 16. The joint module as claimed in claim 6, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 17. The joint module as claimed in claim 7, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 18. The joint module as claimed in claim 8, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 19. The joint module as claimed in claim 9, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 20. The joint module as claimed in claim 10, wherein the joint module has two strain gauges, and the two strain gauges are respectively disposed on the first transmitting assembly and the second transmitting assembly for measuring deformations of the first transmitting assembly and the second transmitting assembly.
 21. A multi joint modular robot arm comprising: multiple joint modules connected in series, and each joint module having a base having a central axis defined in the base; a motion mechanism disposed on the base and having a motion element, a first transmitting assembly, and a second transmitting assembly, and the first transmitting assembly and the second transmitting assembly disposed on the base in parallel and connected to the motion element; wherein the motion element is driven for having a spherical movement centered on the central axis of the base; a linear driving mechanism disposed on the base and having a first linear driving assembly and a second linear driving assembly, and the first linear driving assembly and the second linear driving assembly being non-coaxial and disposed on the base in parallel, and the first linear driving assembly having a first linear moving member connected to the first transmitting assembly; and a first screw assembly connected to the first linear moving member, wherein the first linear moving member is driven by the first screw assembly to reciprocate along the central axis; and the second linear driving assembly having a second linear moving member connected to the second transmitting assembly; and a second screw assembly connected to the second linear moving member, wherein the second linear moving member is driven by the second screw assembly to reciprocate along the central axis; a driving motor assembly disposed on the base and having a first motor having a first output rod and a second motor having a second output rod; and a transmission disposed between the linear driving mechanism and the driving motor assembly, the transmission having a first wheel transmitting assembly connected to the first output rod of the driving motor assembly and the first linear driving assembly; and a second wheel transmitting assembly connected to the second output rod of the driving motor assembly and the second linear driving assembly; and each two joint modules connected in series, and the base of one of said two joint modules connected to the motion element of another one of said two joint modules.
 22. The multi joint modular robot arm as claimed in claim 21, wherein the multi joint modular robot arm has three joint modules connected in series, the three joint modules contain a first joint module, a second joint module, and a third joint module, the first joint module has a rotating driver, the rotating driver is disposed at the second end of the base of the first joint module, the second joint module is disposed between the first joint module and the third joint module, the third joint module has a clamping apparatus, and the clamping apparatus is disposed on the motion mechanism of the third joint module.
 23. The multi joint modular robot arm as claimed in claim 21, wherein in each joint module, the base has a first end and a second end defined along the central axis of the base, the motion element is disposed on the first end of the base, the first output rod of the driving motor assembly, the second output rod of the driving motor assembly, the first linear moving member, and the second linear moving member are juxtaposed in parallel on the base, and the first wheel transmitting assembly and the second wheel transmitting assembly are disposed at the second end of the base.
 24. The multi joint modular robot arm as claimed in claim 23, wherein in each joint module the first motor and the second motor are stepper motors; the first wheel transmitting assembly and the second wheel transmitting assembly are pulley assemblies, sprocket assemblies, or gear assemblies; the first screw assembly has a first screw connected to the first wheel transmitting assembly; and a first barrel disposed between the first screw and the first linear moving member; and the second screw assembly has a second screw connected to the second wheel transmitting assembly; and a second barrel disposed between the second screw and the second linear moving member. 